System for transmitting energy



July. 10,- 1928. 1,677,121

- J." H. HAMMOND, JR

SYSTEM FOR TRANSMITTING ENERGY Original Filed Oct. 31, 1917 111 101. 105 10o Z 1L 141 45125 I 41 145 1.90 159 M 1T 13.; J 135 138 165 136' i :'ll-- I)D U I v 1:7 1 14.3 l 1 INVENTOR RNEY all

Patented July 10, 1928.

UNITED sTAr-es PATE T. orricsi.

JOHN HAYS HAMMOND, .13., or GLOUCESTER,-MASSACHUSETTS.

SYSTEM FOR TRANSMITTING ENERGY.

original application fllfll ttcbersl, 1917, Serial 110.. 199,482. PatentlNo. 1,530,666; Divided and this application filed January 12, 1925., Serial Kohl/(44.

gThis invention relates to a system for r n m e e gyie mer tpart ul y to a transmitting system foxy-multiplex signalling by which is meant: signalling by means of a plurality of independentmessages. simultaneously transmitted.

Theembodiment of the invention hereinafter described, hy-way. of example, is intended;- forn ultiplex telegraphy,

lt has heretofore been proposed to employ in telegraphya series of high frequency carrier waves interrupted at the transmitter.at a. frequency such as to give after detection at a receiver an audible note. of a desired pitch, thus enabling suclra note tohe roducedntthe receiyerwvithqut the crap oy- Inent there of a heterody-ne device or an audio-frequency interrupter. The present invention providesantransmitter at which high frequency. carrier waves are interrupted at a readily-audible frequency and which is furthermore soarranged that during the aiulio-frequcncy interruptions in a series of waves radiated from the. transmitter one or more series of waves of a diiferent frequency or frequencies are radiated. With such an arrangement a plurality of independent messages may be simultaneously transmitted on series o f wayes of different frequencies, each of which is radiated during intervals in the radiation. ofhwaves of the; other frequency or frequencies, so that the.

omurrenccof undesired beatsor otherinterference between waves of different he quenciesis avoided.

In order to achieve theadvantages above indicated, an important feature of the invention resides in the provision in asystem for transmitting energy of a circuit and means for supplying energy tothecircuit jut-he form of a. plurality of series of Wavesfof different frequencies occurring periodically in rotational sequence and each interrupted at a readily-audible frequency. The circuit aboye referred .to is preferablymaderesonant toenergy ofthe different frequencies supplied to it, and to this end the tuning of the circuit may be changed in rotational sequence synchronously with the delivery to the circuit by the supplying means of series of waves of said different frequencies. Moreover, the circuit may have the :forni of an open or otherwise constructed, aerialcircu-it, ai1d the means for supplying energy to -thecircuit is, so constructed asto cause waves of the different frequency or frequencies to occur during the audio-frequency IIItQIIlIPlZlOIlS in the seriesof waves ol each of saidi'requencies. In order to) enah'ie a plurality of messages to be simultaneously transmitted hythe use of the inyentio n meansis also. provided for independently modifying each ot'the series of wayes of said different frequencies in a ccordance ,W-i tlldjil message. i i

A further, important feature of the invention resides in the provision of aresonant circuit which may serve as av radiatingaerial circuit, in ctnnbiination with means for pcriodically changing thetuningof the circuit and key-controlled means r 1; supplying, to thencircuit.fenergy of the t'requencies te which it is periodicallv tuned. A coiwenient means for periodically changing the tuning;

of' the resonant circuit from one to anaccordance. withtl lc principlesoi. the inyeni tion includes means for causing alternating currents oi. d fferent frequencies to beproduced from a source of energy, andfnicans for controlling the generation of the alterv nating currents comprising elements cqperjable respectively when currents of the dif :fcrent frequencies are produced together with separate, manually controlledkeys re spectively connected with the elements and operable to modify inde iendently energy of the different frequencies in accordance with a plurality of different ,messages equal in number to the number of." the different frequencies. Pret'e 'ably, and in the illustrated embodiment of the invention, the means for causing the alternating current generator to produce current of ditl'erent frequencies comprises an oscillatory circuit the tuning of which tletermines the :t'requency of the energy'produccd by the generator.

Still other objects and features of the invention will appear as the description proceeds and will he pointed out in the appended claims.

The single figure of the drawingis a diagrami natic:representation of aradio transmitting system embodying the invention.

In the transmission system illustrated in the drawing, an o en, aerial circuit including an antenna 101 has in series therewith an inductance coil 102, through which the antennais grounded as at 103. The coil 102 forms the secondary of an oscillation transformer 105 including a primary inductance coil 106, which isin a closed, oscillatory circuit including a spark gap device 111 and a variable condenser 112.

The closed circuit 110 is arranged to be energized by any suitable source of direct current as, for instance, a direct current generator 115, one pole otwhich is connected through a choke coil 116 to one side of the variable condenser 112.

For selectively varying thetrequcncy of the oscillations emitted by the open aerial circuit 100 by sin'mltaneously and correspondingly varying the inductance 102 of i the open aerial circuit 100 and the inductance106 of the closed circuit 110, means are provided, including a primary commutator 125, a secondary commutator 126 and an auxiliary commutator 127. These commutators include respectively three co-axial conducting sleeves, 130, 131and 132 which surround and are rigidly secured to but insulated from a shaft 135 arranged to be rotated in fixed bearings 136 at a predei termined rate of, for instance, 1,000 revolutions per second" by any suitable meansas, for instance, an electric motor 138. The motor 138 rotates a comparatively large gear 139 about a fixed axis, this gear 139heing 1 arranged to engage a relatively small gear 140, which is rigidly secured to one end of the shaft 135. Surrounding each sleeve 130,131 and 132 and coaxialtherewith is y aseries of fixed, spaced, conducting segnients 141, 142 and 11.3, which are arranged to be consecutively engaged by corresponding conducting arms 145 rigidly secured to the corresponding sleeves 130, 131 and 132. The segmental conductors l tl, 142and 1413 of the three commutators 125, 126 and 127, and the corresponding arms 145 are so arranged that the three arms 145 are moved simultaneously into and out of engagement with the corresponding segmental conductors 141, 142 and 143, that is, the arms 145 are moved simultai'leously out of engagement with the segmental conductors 141, for instance, and are then simultaneously moved into engagement with the succeeding set of segmental conductors .112. The three scgmental conductors 14-1, 142 and 1 13 of the primary connnutator 12.3 are electrically connected respectively by conductors 116, let? and 11610 three tapslgt), and 151, which are adjustably connected to the primary coil 106., The three segmental conductors 1 H, 142 and l-l2l ot' the secondary commutator '126-are connected respectively by three conductors 15:), 156 and .157 to three taps 158, 159 and 160 which are adjustably connected to the secondary coil 1.02. The primary commutator 125 is provided with a fixed brush 165. which is connected by a conductor 166 to the side of the variable condenser 112" away from the spark gap 111. The secondary commutator 1:26 is provided with a tixed brush 167, which is arranged to engage the corresponding sleeve 131 and which is connected by a conductor 168 to the open,aeri:il circuit 100 at a point 169 hetwcen the secmulary coil 1053 and the ground 103. The three segmental conductors 141, 11:2 and 14-3 of the auxiliary commutator 127 are arranged to be connected selectively to the conductor 166 between the variable condenser 112 and the brush through three conductors 171, 172 and 178, three normally open keys 174, 175 and 176 respectively and a choke coil 17?. The auxiliary connnhtator 127 is in'ovidcd with a fixed brush 180, which is connected by a conductor 181 to the terminal oi the generator 11.1 remote from the choke coil 116.

In the operation of the transmission systexnillustrated' herein the primary and secondary coils106 and 102 areso divided by the corresponding taps 14 9, 150 and 151, and'158,1'50 and 160, that as the arms 145 ot the comn'iutators'125, 126 and 127 are rotated, the open, aerial circuit 102 and the closed, oscillatory circuit 110 are varied successively and in rotational sequence in such a manner that the two circuits are core stantly in propertune and so that the closed circuit 110 including the spark gap device. 111, the variable condenser 112 and more or less of the primary coil 106 caused to oscillate successively at dilt'erent, predctcrmined frequencies. for instance, 1000,000, 800,000 and 900.000 per second, each time that the shaft 135 is rotated through a single revolution. The arrangement is such that when all three keys 171. 175 and 176 are open, the circuitfthrough the generator 115 is open, and cons quently nooscillations are produced in the closed circuit 110 or radiated from the open. aerial circuit 100. but when any one of the keys 174, 175 or 176 is closed. oscillations having a cru'rcspoiuling frequent-e. for instance, of 1,000,000 per seclltll end, are setup inthe closed circuit including the primary commutator 125, the coil 106, the spark gap device 111, and the variable condenser 112. For instance, when the key 174: is closed, the circuit through the generator 1'15 closed each time that the corresponding arm 145 passes over the corresponding segmental. contact 141 of the auxiliary con'nnutator 127, and at thesame time the circuit is closed through the cor responding portion of the primary coil 106, the spark gap device 11.1, variable condenser 112, brush 165, sleeve 130, arm 145, segmental contact 141 of t'he primary connnutator 125,00nductor146 and tap 1 19. Also at the same time the corresponding portion of the open, aerial circuit is short-circuited through the corresponding tap 158,segment 14:1, arm 1&5, sleeve-13l,brush 167 of the secondary commutator 126, and the co'ntluctor 168, to maintain the open, aerial circuit in syntony With the closed, oscillatory circuit 110 as modifiedby the primary commutator 125. Each frequency must be re ceived by a separate station tuned to that particular high frequency. The rate of rotation of the commutator shaft 135 will make this come in audible groups.

Although only one of the many forms in which this invention may be embodied has been shown herein and the corresponding method of operationdescribed, it is to be understood that this invention is not limited to the specific system or to the specific method of operation deseribethbut may be applied in various systems and with various methods of operation without departing from the spirit of the invention orthe scope of the appended claims.

Having described my invention, what I claim is: r

1. In a system for transmitting energy, the combination with an alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator and means for energizing the closed, oscillatory circuit, of means for changing the tuning of said circuit in rotational sequence to different fre quencies, and devices located outside of said oscillatory circuit and operable mamially to modify the energization of said circuit in accordance with a plurality of different messages equal in number to the number of said diflcrent frequencies. f

2. 111 a system for transmitting energy. the combination with an alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator and means for energizing the closed, oscillatory circuit, of means for changing the tuning of said circuit in rotational sequence to different fret uencies. and means for controlling the energization of the oscillatory circuit 1 between s: id instrunn-intalitics and the oscillatory circuit for modifying energy of said. different frequencies in accordance with a plurality of different messages, correspond ing in number with the number of said different frequencies.

3. Ina system for transmitting energy, the combination with an alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator, a sparl: gap in said circuit and means for energiz ing the closed, oscillatory circuit, of means for changing the tuningiof said circuit in rotational. sequence to different frequencies, and means separate from the tuning-changing means for controlling the energiication of the oscillatory circuit, said controlling means comprising commutator sections op erable respectively when the closed, oscillatory circuit is tuned to different frequencies, separate connections between said sections and said oscillatory ci.1'cuit,'and separate manually controlled keys respectively interposed in the connections between said instrumentalities and the oscillatory circuit for niodifying energy of said different the quencies in accordance with a plurality of different messages.

4.111 a system for transmitting energy, the combination with an aerial circuit, of means for making the aerial circuit resonant to a plurality of different frequencies, an

alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator and means for energizing the closed, oscillatory circuit, of means for changing the tuning of said circuit from one to another of said different frequencies, and means separate from the tuning-chang mg means for controlling the energization of the oscillatory circuit, said last-mentioned means comprising instruinentalities operable respectively when theclosed, oscillatory circuit is tuned to different respective fre quencies, connections between said instrumentalitics and said oscillatory circuit and separate uianually-controlled .lceys interposed n the connections bctwcensaid instrunientalitics and the oscillatory circuit for modifying energy of said different frequencies in accordance with a plurality of different n'iessages.

5. In a system for transmitting energy, the combination with an open, aerial circuit of means for making the aerial circuitloo resonant to a plurality of different frequencies, an alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator, a spark gap in said circuit and means for energizing the closed, oscillatory circuit, of means for changing the tuning of said circuit in rotational sequence to different frequencies, and means for controlling the energization of the oscillatory circuit comprising a commutator having sections operable respectively when the closed, oscillatory circuit is tuned to said dili'erent frequencies, separate connections between said sections and said oscillatory circuit, and separate manuallycontrolled keys interposed in the connections between said insta'umentalities and the oscillatory circuit for modifying energy of said different frequencies in accordance with a plurality of different messages respectively.

6. In a system for transmitting energy,

the combination with an aerial circuit, of means for making the circuit resonant to a plurality of diflerent frequencies, means for supplying energy to said circuit comprising an alternating current generator including a closed, oscillatory'eircuit for determining the frequency of the energy produced by the generator, means for successively tuning said closed, oscillatory circuit in rotational sequence to the respective frequencies to which the aerial circuit is resonant, and separate means for modifying energy of the respective frequencies in accordance with messages to be transmitted, and last-men tioned means including a commutator operated in synchronism with the means for tuning the oscillatory circuit to the different frequencies.

7. In a system for transmitting energy, the combination with an aerial circuit, of means for making the circuit resonant to a plurality of different, predetermined frequencies, means for supplying energy to said circuit comprising an alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator, a commutator for successively changing the tuning of said closed, oscillatory circuit in rotational sequence from one to another of said frequencies, a source of direct current, a coinnnltator for controlling the source of direct current in synchronism with changes in the tuning of said closed, oscillatory circuit, said last-mentioned commutator including alternatirely-operative sections, and separate manually-operahle keys corresponding in number with the alternatively-ope ttive sections of the last-mentioned commutator for independently modifying energy of said different frequencies in accordance with different messages.

8. In a system for transmitting energy,

an open, aerial circuit, means for making such circuit resonant to energy of a plurality of diflerent frequencies, means for supplying cnergy to the open, aerial circuit comprising an alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator, means f or changing the tuning of said oscillatory circuit, separate connections for "ausing the oscillator) circuit to be energized at said dili'erent frequencies respectively, said connections including a commutator located outside of the oscillatory circuit and operating in synchronisin with the tuning-changing means, and an independent control device in each of said connections for independently modifying energy of said diti'erent frequencies in accordance with different n'iessages.

9. In a system for transmitting energy, an aerial circuit, means for making the aerial circuit resonant to energy of a plurality of different frequencies, means for supplying energy to the aerial circuit comprising an alternating current generator including a closed. oscillatory circuit for determining the frequency of the energy produced by the generator, means including a commutator for changing the tuning of said closed, oscillatory circuit in rotational sequence so as to cause the generator to produce in rotational sequence energy of the frequencies to which the aerial circuit is resonant, and means for controlling the energization of said closed, oscillatory circuit comprising a commutator having sections corresponding with those of the first-mentioned commutator, separate connections between each of the sections of the last-mentioned commutator and said closed. oscillatory circuit, and a key interposed in each of said connections for indepedently modifying energy of said different frequencies in accordance with different messa es.

10. in a system for transmitting energy, an aerial circuit, means for making the aerial circuit successively resonant to a plurality of diti'erent predetermined frequencies in rotational sequence, said means comprising a commutator and connections between the sections of the commutator and different points of the aerial circuit, means for supplying energy to the aerial circuit comprising an alternating current generator including a closed, oscillatory circuit for determining the frequency of the energy produced by the generator, means including a commutator analogous to the tirstanentioned commutator for changing the tuning of the closed, oscillatory circuit in rotational sequence and in synchronism with changes in the tuning of the aerial circuit so as to cause energy to be supplied to the aerial circuit at diilerent times at the different frequencies to which the aerial circuit is tuned.

ltltl 1 and means for controlling the energization nism therewith, separate connections between the sections of the last-mentioned commutator and the closed, oscillatory circuit and separate manual1y-operable keys intGIPOSGd in said connections respectively for independently modifying the diflerent frequencies produced in the system in accordance with a, plurality of different messages.

JOHN HAYS HAMMOND, JR. 

